Pages 229-238, Language: English, GermanReich, Sven/Troeltzsch, M./Denekas, Th./Wichmann, M.
The introduction of the Cerec 3D software (R 1500) promised the generation of functional occlusion points and proximal contacts on the basis of a 3-dimensional virtual model on the screen. The objective of this in vitro study was to check this claim in the simulated chairside production of a single tooth restoration. Furthermore, the differences both in conventional finishing and in ceramic glazing were to be determined. For the operator, the latter should simplify or shorten the intraoral finishing and polishing of the occlusal surface, or make it superfluous. To check the suitability of the two methods, these were compared with regard to their quality and the time required to perform them. Ten cavities on articulated models, representing real clinical cases, were each provided with two restorations. One was produced with the glazing method (group A), the other conventionally (group B). The Cerec 3D software, version R 1500, was used for designing the restoration. The restorations made from Vita Mark II ceramic blocks were finished with fine diamond instruments and polished with Sof-Lex disks when using the conventional method. In the alternative method, finishing was practically replaced by glazing the surface. The restorations were evaluated in the articulator, considering both the vertical relation at the incisal pin as well as the accurate position of the contact points. The study showed that functional rehabilitation was possible and no significant qualitative differences occurred in the methods. In this in vitro study, it was found that the glazing method reduced the time required by the operator by around 20% and indicates an improvement in quality. The results of this study promise simplification when the glazing method is used clinically.
Keywords: 3D occlusal surfaces, glazing, quality assessment, time expenditure
Pages 239-251, Language: English, GermanAsselmeyer, Theresia/Fischer, V./Matthies, H./Schwestka-Polly, R.
The present study examines the extent to which computer-assisted learning units provided independently of place and time are used in self-study as a supplement to the classical classroom instruction of dental students. Indications as to whether such teaching modules improve training in orthodontics should be obtained from this.
Attention was focussed on the implementation and evaluation of the "Orthodontic set-up" teaching module, which can be accessed in the Internet and Intranet of the university. The didactic arrangement offered classical university courses in parallel (four lectures on the subjects of occlusion, function, diagnostics, and therapy) in addition to the electronically communicated teaching contents. In addition, intensive supervision during the production of the set-up was guaranteed.
The use of this multimedia learning concept was in general assessed positively by 63 surveyed students in the 2002/03 winter semester. The results revealed on the one hand the intensity of use and features of the acquisition of knowledge (use types), and on the other hand, in terms of professional relevance, the contents were found to be well explained, didactically attractive, and understandably presented. However, numerous drawbacks were also mentioned (technical and time problems; qualification deficits).
The experience gained in this project should encouragemore future investment in the development of alternative university didactic models.
Keywords: computer-assisted teaching, e-learning, orthodontics, occlusion, set-up
Pages 253-262, Language: English, GermanSchultze-Mosgau, S./Thorwarth, W. M./Grabenbauer, G. G./Amann, K.
The demonstration of patient case reports in the course of a clinical round is an essential part of teaching medicine and dentistry. However, suitable live patients with particular problems are not always available at a time when teaching is taking place. This project therefore had the objective of establishing a web-based, virtual e-learning concept for demonstrating case reports independent of time and place, with the possibility of an interactive examination, diagnosis, and interdisciplinary therapy decision making for medical and dental students.
Anonymized case reports of diseases in the oral and maxillofacial region and the interdisciplinary treatment were digitized and prepared in a web-based format. The technical aspect was based on connecting flash modules with videos and animation, and monitoring through HTML and Javascript. Due to the modular concept and the programming used, the learning environment was independent of platform and open. Independent formats (.swf, .avi, .mpeg, etc.) were integrated into the individual modules. According to a hierarchic decision system, the user was guided interactively to the diagnosis through a differential diagnostic exclusion process. Sound was digitized and integrated inmp3 compressed formin the 3Dmodels for lip-synchronous speech output. The speech output was connected with a virtual 3D tutor that acted in an advisory capacity in reaching a diagnosis and determining therapy. Further sources of informationand literature with abstracts or pdf files of the subject-related publications were inserted to ensure that the teaching was objective. To conclude the virtual clinical round, a check on learning success was conducted in the formof amultimediamultiple choice test.
Keywords: e-learning, teaching, internet, clinical round, online test, dentistry, medicine
Pages 263-267, Language: EnglishHuang, Li Chung
This report presents the use of Cerec veneers in the treatment of a female patient suffering from tetracycline staining and an anterior open bite. Because the latest Cerec 3D software did not include a veneer design program, only a correlation mode, the Cerec 3 veneer program was used.
Pages 293-301, Language: English, GermanDevigus, A./Lombardi, G.
Vollkeramische Versorgungen sollten die Farbe der natürlichen Zähne möglichst gut reproduzieren, um eine Wiederherstellung nach den ästhetischen Wünschen und Vorstellungen des Patienten zu ermöglichen. Die Grundfarbe von Zirkonoxid ist weiß bis elfenbein. Eine Farbanpassung kann teilweise durch die Verblendung mit keramischen Materialien erfolgen. Besser wäre es aber, wenn bereits das Gerüst dem Grundfarbton der Nachbarzähne angepasst werden könnte. In dieser Arbeit wurde der Einfluss verschieden eingefärbter Gerüste aus Y-TZP der Firmen Vita, 3MESPE und von Enrico Steger (ohne, mit 0,5mm bzw. 1,0 mm keramischer Verblendung mit Base Dentin) auf die Helligkeit, die Sättigung und den Farbton (= Value, Chroma und Hue) mit Hilfe eines Spektralfotometers (EasyShade, Vita) an einem klinischen Fall im Mund und auf dem Modell gemessen und bewertet. Die Einfärbung von Gerüsten aus Y-TZP kann durch die entstehende Anpassung an denGrundton helfen, die zur Erzielung der gewünschten Farbe notwendige Schichtstärke der Verblendkeramik zu reduzieren und sollte in Zukunft routinemäßig durchgeführt werden. Damit können die Präparationen der Zähne substanzschonender durchgeführt werden, ohne eine Verschlechterung des ästhetischen Resultates in Kauf nehmen zu müssen.
Keywords: Einfärben, Zirkonoxid, Gerüste, Vollkeramik